Higher HbA1c levels & mortality

Higher HbA_1c levels predict better outcomes in advanced heart failure with diabetes by Marlene Busko

APRIL 12, 2012 Marlene Busko

Los Angeles, CA - Patients with advanced heart failure who were also diabetic had better two-year survival if their baseline glycated hemoglobin (HbA_1c) levels were >7.3% in a new study [1]. Among the nondiabetic patients with heart failure, HbA_1C levels did not predict survival outcomes. The retrospective cohort study is published online March 27, 2012 in the American Journal of Cardiology.

"We're finding that in heart failure [plus diabetes], higher HbA_1C levels are associated not with worse outcomes, but with better outcomes," lead investigator Dr Tamara Horwich (University of California, Los Angeles) told heartwire. This suggests that for patients with both diseases, "the focus should not be on lowering the HbA_1C levels to as low as possible," she said, adding that "aiming for a midrange of 7.2% to 8.2% may be very reasonable."

This "adds to a small but growing body of literature demonstrating a complex relationship between levels of glycemic control and survival in patients with advanced, established heart failure," Dr David Aguilar (Baylor College of Medicine, Houston, TX), who was not involved with this research, told heartwire. However, because it was an observational study, residual confounding factors may be contributing to adverse outcomes.

The implications for clinical practice are that "in someone with advanced heart failure who may be having difficulties with hypoglycemia or other adverse effects of diabetic medications, less stringent glycemic control (HbA_1C <8%) may be acceptable," he said. On the other hand, "if patients are tolerating the medications without difficulties, current glycemic guidelines should continue to be followed as we await further information from prospective clinical trials."/.../